1. Field of the Invention
The invention relates generally to animal litters and particularly to extruded animal litters having an increased absorption rate.
2. Description of Related Art
Extruded animal litters are known in the art. U.S. Pat. No. 3,923,005 discloses an animal litter comprising alfalfa and starch that is made using an extrusion process. U.S. Pat. No. 4,206,718 discloses a process for producing light weight animal litter from ground alfalfa and gelatinisable flour or starch. In one embodiment, the litters contain up to 10% bentonite as a binder. U.S. Pat. No. 5,452,684 and U.S. Pat. No. 5,577,463 disclose an animal litter comprising an extruded smectite clay that forms stronger clumps when wetted with animal urine. U.S. Pat. No. 7,603,964 discloses mixing a clay materials and a light-weighting material and forming the mixture into a composite particle using various methods such as agglomeration, compaction, and extrusion. WO2009133212A1 discloses methods for producing low-density agglomerated pet litters using minerals with an attapulgite content greater than 50% and an extrusion process. U.S. provisional patent application 61/337,019 discloses an extruded animal litter made from clay and starch.
Generally, these extruded litters perform well for their intended purpose, e.g., absorbing liquid animal waste such as urine. However, many of the extruded animal litters, particularly those made from clay and starch, have a “film” on the surface of the litter particles. While this film is useful for various purposes, e.g., reducing the dust created while using the litter, it often adversely affects the absorption rate of the litter. There is, therefore, a need for methods for increasing the absorption rate of extruded animal litters and new extruded animal litters having an increased absorption rate.